| Number | Name | Date | Kind |
|---|---|---|---|
| 3370140 | Betts | Feb 1968 | |
| 3467940 | Wallo | Sep 1969 | |
| 3512043 | Jaaksoo et al. | May 1970 | |
| 3912889 | Bright | Oct 1975 | |
| 4070557 | Ostapovitch | Jan 1978 | |
| 4106074 | Conne | Aug 1978 | |
| 4170939 | Hoheisel et al. | Oct 1979 | |
| 4271453 | Yajima et al. | Jun 1981 | |
| 4358135 | Tsuge et al. | Nov 1982 | |
| 4369707 | Budde | Jan 1983 | |
| 4906203 | Margrave et al. | Mar 1990 | |
| 4988307 | Muzslay | Jan 1991 |
| Entry |
|---|
| IBM Technical Disclosure Bulletin, vol. 7, No. 6 of Nov., 1964. |